The present invention relates to a F. necrophorum bacterin, to a process for the production thereof and to a method of treating Fusobacterium disease with this bacterin.
Fusobacterium necrophorum (formerly referred to as Sphaerophorus necrophorus) is an obligate anaerobic gram negative rod, which is generally recognized as playing a significant role in a variety of disease entities affecting ruminants including Chronic Footrot in sheep, Acute and Chronic Footrot in cattle, Liver Abscess in cattle, and Diphtheria in calves.
Garcia et al discloses in "Biological Characterization of Fusobacterium necrophorum Cell Fractions in Preparation for Toxin and Immunization Studies", Infection and Immunity, April 1975, pages 609-616, that preliminary trials indicated that an alum-precipitated toxoid derived from the cytoplasm of bovine liver abscesses reduced liver abscesses to a level of 10% as compared to the 35% level of the control sample.
Abe et al discloses in "Immunization of Mice Against Fusobacterium necrophorum Infection by Parenteral or Oral Administration of Vaccine", Am. J. Vet. Res., Vol. 39, No. 1, pages 115-118 (January 1978) a vaccine made with whole cell suspensions of formalin-killed F. necrophorum. This vaccine was administered by three different routes: intraperitoneal injection of the killed cells in a saline solution, intraperitoneal injection of the killed cells with added aluminum hydroxide adjuvant and by feeding as a powder to which lyophilized bacterial cells had been added. However, even the most effective treatment (i.e., IP injection of cells plus adjuvant) resulted in mortality rates of almost 40% after seven days post challenge. These bacterins have not, however, shown sufficient efficacy when tested under field conditions to be of commercial value.
Katitch reports in "Etude comparative sur la valeur prophylactique de 2 vaccins contre le pietin du mouton", Bull. Soc. Vet. et Med. comparee, Vol. 76, No. 4 (Lyon 1974), the results of a comparison of two commercial vaccines against Foot-Rot in field studies. One of the vaccines contained only one antigen and was found to be almost completely ineffective. The second vaccine was a multiple antigen preparation in which S. necrophorus, Staphylococcus pyogenes and W. perfringens were included.
U.S. Pat. No. 4,061,751 discloses a treatment for foot rot and liver lesions in ruminant animals in which a 6-substituted 3-nitroimidazo[1,2-b]pyridazine is administered to the animal being treated. The preferred method of administration is oral administration.
To date, however, no effective prophylactic agent to control or prevent F. necrophorum diseases is commercially available.